The analysis of the changes of maternal thyroid autoantibodies during early pregnancy

Abstract

Objective To investigate the changes and related factors of maternal thyroid autoantibodies during early pregnancy. Methods Urinary iodine concentration(UIC), serum thyroid stimulating hormone(TSH), free thyroxine(FT4), thyroid-peroxidase antibody(TPOAb), thyroglobulin antibody(TgAb)concentrations were determined in 7 190 women during early pregnancy in an iodine-sufficient region of China. Results The prevalence of TPOAb positivity and TgAb positivity were 8.7% and 12.0% respectively. The prevalence of overt hypothyroidism and subclinical hypothyroidism increased significantly in group of thyroid antibody positivity. The prevalence of TPOAb positivity and TgAb positivity presented a U-shaped curve, ranging from mild iodine deficiency to iodine excess, especially increased significantly in the group with UIC<100 μg/L. Conclusion Prevalence of thyroid antibodies positivity became higher during early pregnancy. The positive thyroid autoantibodies during pregnancy were significantly associated with maternal hypothyroidism. Both iodine excess and iodine deficiency are risk factors of positive thyroid antibodies. (Chin J Endocrinol Metab, 2016, 32: 376-379) Key words: Thyroid; Pregnancy; Thyroid antibody; Iodine